• Animal Bioscience
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• v.36 no.9
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• pp.1435-1444
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• 2023

Objective: This study was conducted to evaluate Raman spectroscopy technique as a noninvasive tool to predict meat quality traits on Braford longissimus thoracis et lumborum muscle. Methods: Thirty samples of muscle from Braford steers were analyzed by classical meat quality techniques and by Raman spectroscopy with 785 nm laser excitation. Water holding capacity (WHC), intramuscular fat content (IMF), cooking loss (CL), and texture profile analysis recording hardness, cohesiveness, and chewiness were determined, along with fiber diameter and sarcomere length by scanning electron microscopy. Warner-Bratzler shear force (WBSF) analysis was used to differentiate tender and tough meat groups. Results: Higher values of cohesiveness and CL, together with lower values of WHC, IMF, and shorter sarcomere were obtained for tender meat samples than for the tougher ones. Raman spectra analysis allows tender and tough sample differentiation. The correlation between the quality attributes predicted by Raman and the physical measurements resulted in values of R² = 0.69 for hardness and 0,58 for WBSF. Pearson's correlation coefficient of hardness (r = 0.84) and WBSF (r = 0.79) parameters with the phenylalanine Raman signal at 1,003 cm^-1, suggests that the content of this amino acid could explain the differences between samples. Conclusion: Raman spectroscopy with 785 nm laser excitation is a suitable and accurate technique to identify beef with different quality attributes.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1668-1672
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• 2013

We developed a standoff Raman detection system for explosive molecules (EMs). Our system was composed of reflective telescope with 310 mm diameter lens, 532 nm pulse laser, and Intensified Charge-Coupled Device (ICCD) camera. In order to remove huge background noise coming from ambient light, laser pulses with nanosecond time width were fired to target sample and ICCD was gated to open only during the time when the scattered Raman signal from the sample arrived at ICCD camera. We performed standoff experiments with military EMs by putting the detector at 10, 20 and 30 m away from the source. The standoff results were compared with the confocal Raman results. Based on our standoff experiments, we were able to observe the peaks in the range of 1200 and $1600cm^{-1}$, where vibrational modes of nitro groups were appeared. The wave numbers and shapes of these peaks may serve as good references in detecting and identifying various EMs.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.87.2-87.2
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• 2016

As an era of nano science approaches, the understanding on the shape and optical properties of various materials in a nanoscale range is getting important more seriously than ever. Accordingly the development of high spatial-temporal-spectral resolution measurement tools for characterization of nanomaterials/structures is highly required. Generally, the various properties of sample can be measured independently, e.g. to observe the structural property of sample, we use the scanning electron microscopy or atomic force microscopy, and to observe optical property, we have to use another independent measurement tool such as photoluminescence spectroscopy or Raman spectroscopy. In the case of nano-materials, however, it is very difficult to find out the same position of sample at every different measurement processes, and the condition of sample can be changed by the influence of first measurement. The tip enhanced Raman scattering(TERS), which can simultaneously measure the two or more information of sample with nanoscale spatial resolution, is one of solutions of this problem. In this talk, I will present our recent nano Raman scattering data of graphene that measured by TERS and optimized tip fabrication method for efficient experiment.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.5
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• pp.223-228
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• 2002

We have studied the characteristics of Raman scattering spectroscopy from $_ZnS{1-x}Te_x$ alloys in the whole range of Te composition x. The Raman spectra showed two-mode behaviors for those alloys. The Raman line shape showed the changes of an asymmetry and broadening of that with Te composition x. The asymmetric broadening of the line shape could be explained with a spatial correlation model.

• Electrical & Electronic Materials
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• v.10 no.3
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• pp.284-288
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• 1997

FT-IR and FT-Raman spectra were measured for 15Li$_{2}$O.3Al$_{2}$O$_{3}$.78SiO$_{2}$. 4K$_{2}$O glass system after UV irradiations. Optimum UV irradiation time of Li$_{2}$O.SiO$_{2}$ crystalline phase was 60 seconds and crystalline phase of Li$_{2}$O.SiO$_{2}$ was leached out on 5% HF. 977 cm$^{1}$ band of FT-Raman spectra can be attributed to two-non bridging oxygen in unit cell for 1 hour and optimum crystallization was confirmed for 3 hrs, 630.deg. C.

• Molecules and Cells
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• v.26 no.6
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• pp.530-535
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• 2008

Optical signals based on Raman scattering, coherent anti-Stokes Raman scattering (CARS), and harmonic generation can be used to image biological molecules in living cells without labeling. Both Raman scattering and CARS signals can be used to detect frequencies of molecular vibrations and to obtain the molecular distributions in samples. Second-harmonic optical signals can also be generated in structured arrays of noncentrosymmetric molecules and can be used to detect structured aggregates of proteins, such as, collagen, myosin and tubulin. Since labeling techniques using chemical and biological reactions may cause undesirable changes in the sample, label-free molecular imaging techniques are essential for observation of living samples.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.423-427
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• 2003

In this paper, we have investigated the output characteristics of the Stokes Raman laser in hydrogen, deuterium, and their mixed gases as a function of the incident pump energy and gas pressure using KrF excimer laser as pumping source for generating the differential absorption lidar (DIAL) wavelengths suitable in measuring the ozone concentration of the troposphere. The optimization results of compact excimer-Raman laser transmitter in DIAL system for the tropospheric ozone sounding at the 292 nm/319 m and 292 nm/313 nm wavelength pairs are presented. for the ozone sounding in the 4-12 km range, it has been demonstrated that the design of transmitter for DIAL lidar may be significantly simplified by the use of 292 nm/319 nm wavelength pair. The investigations of Raman scattering in the mixture of hydrogen and deuterium gases have shown that such mixture may be efficiently used for developing the multi- wavelength light sources for DIAL systems.

• Journal of the Optical Society of Korea
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• v.13 no.3
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• pp.316-320
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• 2009

A novel broadband wavelength-swept Raman laser was used to implement Fourier-domain mode locked (FDML) swept-source optical coherence tomography (SS-OCT). Instead of a conventional semiconductor optical amplifier, this study used broadband optical fiber Raman amplification, over 50 nm centered around 1545 nm, using a multi-wavelength optical pumping scheme, which was implemented with the four laser diodes at the center wavelengths of 1425, 1435, 1455 and 1465 nm, respectively, and the maximum operating power of 150 mW each. The operating swept frequency of the laser was determined to 16.7 kHz from the FDML condition of 12 km optical fiber in the ring cavity. The OCT images were obtained using the novel broadband wavelengthswept Raman laser source.

• Polymer(Korea)
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• v.26 no.6
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• pp.752-758
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• 2002

FTIR, FT-Raman, and X-ray diffraction techniques were used to determine chain segregations and lamellar structures of the mixed binary n-paraffins with different chain lengths. The results of three different techniques, infrared spectroscopic studies of crystal field splitting, the Raman longitudinal acoustic mode, and the SAXS long period measurements were compared one another to understand the crystallization mechanism of separated or mixed n- paraffin lamellae.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.52-55
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• 1997

In this study, PLZT stock solutions were prepared by sol-gel processing to fabricate PLZT thin films. The stock solutions were spin-coated on ITO-glass and the film were annealed by rapid thermal annealing(RTA). The variation of tile crystallographic structure of the thin films and the phase transition with respect to it were observed using Raman spectra. Raman result showed that the band of spectra are broad as the amount of Zr substitution increased and specially, abrupt change occurs in the raman spectra upon crossing the tetragonal-rhombohedral phase boundry at 2/55/45 PLZT thin film. So, the fact that the crystallographic structure was transitted from tetragonal to rhombohedral structure was certified.